Majoritarian politics

Income tax:
Pays: everyone
Benefits: almost everyone

Conservatives feel: would tend to prefer a flat tax. Also, they feel that it is wrong that not everyone is paying taxes. Many conservatives feel that if everyone had to pay taxes, less people would support a big government.

Liberals feel: aren't as upset about the income tax because they believe more strongly in welfare and don't mind paying more tax to help people. The liberals also tend to support a bigger government so income tax for them is a plus.